Bullet Weight...

[trevor]

Hi, experts...I'm going to expose my ignorance and ask a question. If there's a reference where I can go, please point me in the right direction.

All other things being equal, what are the implications of differing bullet weight. For example, suppose I wanted to use 9mm ammo that comes in 115, 124, or 147 grain weights.

What principle would guide my selection, assuming they all feed well.

And, if I had 2 cc firearms, one with a 3.1" barrel, and one with 4.02" barrel length, would one cartridge work for both (again, assuming feed performance is flawless.) or is that a bad idea?

 Thanks!

[GunEnvy]

Well Trevor, how many answers are you ready to read? there are a few different schools of thought on this one. 1) the faster the bullet, semi regardless of weight, is better due to better penetration.
2) The heavier the bullet, regardless of velocity gives better penetration.
There are those that feel a bullet like a 9mm going at 1100fps or so will give better stopping power and there are those that feel a 200 grain 45 going at 950fps will give better stopping power. Born of those two fights was the original 10mm, 45 size bullets going at 9mm speed(these are approximates, just to keep the 10mm guys from jumping on me). When the original 10mm failed the 40 was born, larger bullet going fast.
Some of thought behind the 9's is that with the speed they will go deeper into the body, creating more damage. Larger bullet people feel that the heavier bullets like the 45's will go thru more dense body parts such as bone and cartilidge, creating more damage. Within each caliber the thoughts are the same, 115 gr bullets will go deeper but the 147gr people will say the smaller bullets may richochet off of bone. It really somes down to researching actual shootings with each load and bullet design.

As far as the barrel length is concerned with ballistics, that one is alittle easier. The shorter the barrel the slower the bullet will travel. The bullet will exit the tube before all of the powder has burnt, reducing velocity. My school of thought on this one is to use lighter bullets on compact size guns to offset some of the velocity loss. But again research real world shootings and see which bullet design performs best. Hope that helps and I'm sure you'll get a ton of answers... All of them will be right and all will be wrong, depending on who you ask

[trevor]

Thanks very much, GunEnvy,  for your detailed reply. Let me state what I think I heard so you can tell me if I got it right (or wrong!) Is there a source that you know to research shootings other than the anecdotes in gun and leo magazines?

1) within a caliber, lighter is faster, faster is generally better, but 'too' light may be deflected by denser tissue and may be less effective at stopping.

2) across calibers, heavier is less susceptible to 'dense tissue deflection.'

This leads me here: given my selection of cartridge size (9mm, chosen for low ammo cost and ease of cc), and given the short length of one of my barrels, 115 grain would seem to make the best use of that short barrel. The caveat being that the lighter bullet weight may be more subject to dense tissue deflection.

So, my logic leads me to a lighter bullet, eyes open to the deflection possibility. Since center of mass is where I'm aiming for SD, deflection shouldn't prevail as an overriding concern anyway, since center of mass is all about soft tissue? Or, do ribs and sternum trump velocity?

Or....am I over-thinking this?

[GunEnvy]

if you google "one shot stops" you should come across a whole bunch of info. I know one test that was done was called the Stroudsburg tests. In that test the people shot live goats to test bullet performance.
Yes center body is where you want your shots to go in a SD situation but like you say, ribs can play a part in deflecting the bullet. And than to add to it, clothes can also effect bullet performance. Fabric can fill up the hollow point decreasing bullet expansion. IMHO I do think people put too much thought into bullet selection. Check out some of those tests on bullet performance and you'll see the myriad of testing procedures. This bullet performs well on light clothing but performs poorly against windshields. This bullet performs well on heavy clothing but poorly against light clothing. Then there will be the bullets that seem to perform well in all conditions, then you'll cee another test where that bullet didn't perform as well. And many of the tests are done thru a 5 in barrel, so how do you scale it down to mean something in my 3 in barrel.  In one of my guns I carry the Hornady self defense (something like fxtp) it has a polymer core built into the hollow point to ensure expansion thru clothing. I figure hornady spent millions bringing that ammo to market, I'm sure they tested it in as close to real life conditions as they could.
IMO the best test is to take one light bullet and one heavy bullet and try to see how many people will volunteer to be shot with each one, count the results and carry the one with the least votes

[Schmenge]

Another consideration is accuracy. You should shoot some of each in both guns. Look for accuracy and recoil. Any of those bullets will do the job IF you hit where you're aiming. Since you may need a second shot in a hurry, recoil is an important factor. Shot placement is the most importand consideration. Choose the round that works best in your guns. It's a good excuse to go to the range anyway!

[trevor]

Thanks Schmenge and GunEnvy.

Funny, I actually was already considering changing to Hornady Custom Ammunition 9mm Luger 115 Grain XTP Jacketed. I think you mentioning it put me over the decision making hump. Now I just have to find some and test it!

Your replies make me think this is a reasonable choice, at least till I win the lottery and get a 1911. But, I wonder if I can bring a goat next time i go to ommenlanden?

[trevor]

Hmm. My internet search led me to find that apparently no one has the Hornady Custom Ammunition 9mm Luger 115 Grain XTP Jacketed in stock!

I did find Fiocchi Extrema Ammunition 9mm Luger 115 Grain Hornady XTP Jacketed Hollow Point Box of 50 at midwayusa. Does Fiocchi take the hornady bullets and manufacture them into their own brass? Any reason these are, or are not, any good?

Trevor

[GunEnvy]

I think most of the bullet manufacturers sell their bullets to other companies. I know you can get speer bullets loaded be others so I imagine hornady does the same. How much are you planning to buy, if just a few boxes it may be cheaper to go to an area gun store to pick up.

[trevor]

Not looking for too much, maybe a few boxes. Want to run through enough to trust it.

Good point about getting it locally, I like to keep the local places in business. I didn't know if this was available nearby; I will definitely call around.